Stepped Attenuator
Oct 8, 2007 at 2:20 PM Thread Starter Post #1 of 11

Cecala

Headphoneus Supremus
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Can somebody state the difference in sound output between each step in the Stepped Attenuator in dbs please.
Also how firm is the clicking action and how load is this sound?
 
Oct 8, 2007 at 7:23 PM Post #2 of 11
In my HR Home the step is 1.5dB, maybe a tad more, I was measuring music level so the SPL meter output was not that steady.
It makes no sound, turns easily and smoothly without clicking action.
 
Oct 9, 2007 at 11:03 AM Post #3 of 11
No sound -- firm action (smooths up somewhat with use) -- beginning steps (off to 10 or 11 AM) seem to have slightly larger differences between them, than later steps (after 11 to end).
From what I've read, it seems that many attens are designed this way, with variable-value steps.
Or maybe that's just how it sounds to *me* on my HR Desktop w/Home module.
 
Oct 10, 2007 at 11:00 AM Post #4 of 11
Quote:

Originally Posted by silverrain /img/forum/go_quote.gif
No sound -- firm action (smooths up somewhat with use) -- beginning steps (off to 10 or 11 AM) seem to have slightly larger differences between them, than later steps (after 11 to end).
From what I've read, it seems that many attens are designed this way, with variable-value steps.



Don't you mean the other way round as it begins with small steps and later they are larger in progression(DBs)?
 
Oct 10, 2007 at 11:07 AM Post #5 of 11
No -- it is just as I wrote it.
If I switch from high to medium gain, and select steps around 3 PM area, the steps are slightly smaller, and allow more precise control, if I have to go this route, which I never do, but I could if I needed to.

BOTTOM LINE:
The steps all the way around are pretty close, anyway, and really isn't a source of concern for me. If I switch between high and medium gain, I get even more precise control.
Like I said, I've read several times that many designs are made to have variable differences in the steps. I dn't remember if it applied specifically to HR controls.
Why don't you ask HR, if you need to know for sure whether there are variable steps used? And let us know here.
 
Oct 10, 2007 at 11:19 AM Post #6 of 11
Tyll,
I am on the verge of ordering the Desktop Max+Max but have come to a halt regarding the Stepped Attenuator option. On your web space you state that the 'Shunt' type of Attenuator was chosen because the number of contacts is minimized. Does this type incorporate the so-called "Make before Break" to reduce the switching noise or does this not apply to the 'Shunt' variant? And how if so does this affect the sound, does it 'click' as you turn the knob?
Secondly what difference in DBs is there between each step and I assume this varies according to were you are around the 'Clock'. Smaller at the start and larger as you proceed?
 
Oct 11, 2007 at 2:18 AM Post #7 of 11
Quote:

Originally Posted by Cecala /img/forum/go_quote.gif
Tyll,
I am on the verge of ordering the Desktop Max+Max but have come to a halt regarding the Stepped Attenuator option. On your web space you state that the 'Shunt' type of Attenuator was chosen because the number of contacts is minimized. Does this type incorporate the so-called "Make before Break" to reduce the switching noise or does this not apply to the 'Shunt' variant? And how if so does this affect the sound, does it 'click' as you turn the knob?
Secondly what difference in DBs is there between each step and I assume this varies according to were you are around the 'Clock'. Smaller at the start and larger as you proceed?



Yeah, Joe's going to have to answer that one on the dB/step. I've got a spreadsheet somewhere, but it's old and I'm pretty sure the values have changed since then.

In terms of the way the attenuator works, it minimizes the connections because the resistor attenuator uses one common resistor on the board, and changes the other resistor on the attenuator. They can develop a little click or pop, but once they're in position they're rock solid.
 
Oct 11, 2007 at 2:54 AM Post #8 of 11
Just my 2¢, I used one HR's steppers for a while when I had a balanced desktop on loan, the noise while changing volume was never an issue for me while listening with a variety of headphones.
 
Oct 11, 2007 at 4:38 PM Post #9 of 11
Here are the specs from JoeW; Hope this helps, ya'll!
cool.gif


Stepped Attenuator steps, change in dB:
1 to 2N/A
2 to 39.89
3 to 47.33
4 to 55.12
5 to 63.44
6 to 71.53
7 to 81.48
8 to 91.43
9 to 101.58
10 to 111.56
11 to 121.54
12 to 131.29
13 to 141.69
14 to 151.49
15 to 161.73
16 to 171.54
17 to 181.45
18 to 191.84
19 to 201.54
20 to 211.65
21 to 221.85
22 to 231.70
23 to 241.87


Cheers,
Jorge
HR Sales/Product Manager
 
Oct 12, 2007 at 4:58 AM Post #10 of 11
Quote:

Originally Posted by n_maher /img/forum/go_quote.gif
Just my 2¢, I used one HR's steppers for a while when I had a balanced desktop on loan, the noise while changing volume was never an issue for me while listening with a variety of headphones.


Thanks, Nate. We've discovered you have to be very careful when building them and getting them lubed and sealed up so that the don't develope clicks. But the truth is we use a very pure and simple circuit, and if it gets dirty it may develope a pop. So ... DON"T SMOKE IN YOUR LISTENING ROOM! No, seriously, high-end headphone amp makers make hot-rods, and hot-rods sometimes need tweeking to work; so you can expect an attenuator to develop a click here or there over time. We probably build in more protection-like things (like having learned to be super careful when we build stepped attenuators) than many makers. I was just saying that if they do start to tick a bit --- and this probably goes pretty much for any high-end SA in any good makers amp --- don't worry, they'll be rock solid once they make contact in position.
 

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